OVERVIEW: The 53-51 is a Soviet pattern-running, heavyweight torpedo developed in 1952 for submarine and surface ship use against enemy vessels. It features active pattern-running movement to increase hit probability without onboard homing.

DETAILS: The designation "53-51" indicates a 53 cm diameter and design initiation in 1951. It was developed as an improvement over straight-running torpedoes by incorporating pattern-running logic to cover larger target areas. Once launched, the torpedo followed a pre-set zig-zag search pattern to increase the chance of hitting maneuvering or escorted ships. It used a wet-heater propulsion system and carried a high-explosive warhead with contact and magnetic influence fuzing.

TYPE: Heavyweight pattern-running torpedo

FUNCTION: After launch, the 53-51 runs straight for a preset distance before initiating a zig-zag pattern search to sweep a wider area. It was intended for use against surface ships, relying on contact or magnetic detonation without guidance or terminal homing.

NOTE:
IOC: 1941 (53-39 base), 1952 (53-51)
Operators: Soviet Union
Platforms: Project 613 (Whiskey-class), Project 611 (Zulu-class) submarines
Conflict used in: No confirmed wartime use

SOURCE:
Jane’s Underwater Warfare Systems ; Federation of American Scientists (FAS): https://fas.org/man/dod-101/sys/ship/weaps/index.html ; Russian Navy Historical Archives ; Naval Institute Guide to World Naval Weapon Systems